• 한국결정성장학회지
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• 제8권1호
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• pp.117-123
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• 1998

초크랄스키 실리콘 기판의 뒷면에 형성된 기계적 손상이 미치는 효과에 대하여 고찰하였다. 기계적 손상의 정도는 레이저 여기/극초단파 반사 광전도 감쇠법에 의한 소수반송자 재결합 수명, 광열범위, X-선 단면 측정 및 습식산화/선택적 식각 방법으로 평가하였다. 그 결과, 웨이퍼 뒷면에 가해지는 기계적 손상의 세기가 강할수록 소수반송자 재결합 수명은 짧아지고, 광열 변위의 평균값은 비례적으로 증가하였으며, 손상된 웨이퍼에서 Grade 1의 과잉 광열 변위값을 1로 봤을 때 과잉 광열 변위의 정규화한 상대 정량 비는 Grade 1: Grade 2:Grade 3 = 1:19.6:41이다.

• Archives of Pharmacal Research
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• 제6권2호
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• pp.109-114
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• 1983

A mechanism of taurine transfer across the rat small intestine was elucidated by using the in situ recirculation perfusion or loop method. Taurine uptake was saturable, Km= 39.9 mM, and energy dependent, and required sodium. The close structural analogues, aminomethane sulfonic acid, .gamma.-amino-butyric acid, hypotaurine, and .betha.-alanine, reduced significantly taurine uptake when present in 10-fold excess. The .alpha.-amino acid, glycine, did not inhibit uptake. Hence, all of these findings lead to a conclusion that a carrier-mediated transport system for taurine exists in the small intestine.

• 한국전기전자재료학회논문지
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• 제20권3호
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• pp.257-262
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• 2007

Organic light-emitting diodes (OLEDs) with the high efficieney and long lifetime are of growing interest in next-generation displays. Among the factors influencing OLEDs properties, one of unstable factor is $Alq_3$ cationic species caused by the excess holes resided in $Alq_3$ layer. Therefore, we suppressed the accumulation of excess holes by using the mixed-hole transporting layer (MHTL) of NPB and CBP in multilayer green OLEDs. The devices with MHTL showed improved characteristics in the luminous efficiency and lifetime. More characteristics and the carrier transport mechanism will be discussed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.467.1-467.1
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• 2014

Quantum dots (QD) solar cells has received considerable attention due to their potential of improving the overall conversion efficiency by harvesting excess energy via multiple excitons generation (MEG). Although there have been many reports which show MEG phenomena by using optical measurement of quantum dots themselves, carrier multiplication in real QD photovoltaic devices has been sparsely reported due to difficulty in dissociation of excitons and charge collection. In this reports, heterojunction QD solar cells composed of PbS QD monolayer on highly crystalline $TiO_2$ thin films were fabricated by using Langmuir-Blodgett deposition technique to significantly reduce charge recombination at the interfaces between each QD. The PbS CQDs monolayer was characterized by using UV-vis, transmission electron microscopy (TEM) and atomic force microscopy (AFM). The internal quantum efficiency (IQE) for the monolayer QD solar cells was obtained by measurement of external quantum efficiency and determining light absorption efficiency of active layer. Carrier multiplication was observed by measuring IQE greater than 100% over threshold photon energy. Our findings demonstrate that monolayer QD solar cell structure is potentially capable of realizing highly efficient solar cells based on carrier multiplication.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1121-1129
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• 2008

A series of steady-state and short-term experiments on a three-phase circulating-bed biofilm reactor (CBBR) for removing toluene from gas streams were conducted to investigate the effect of macroporous-carrier size (1-mm cubes versus 4-mm cubes, which have the same total surface area) on CBBR performance. Experimental conditions were identical, except for the carrier size. The CBBR with 1-mm carriers (the 1-mm CBBR) overcame the performance limitation observed with the CBBR with 4-mm carriers (the 4-mm CBBR): oxygen depletion inside the biofilm. The 1-mm CBBR consistently had the superior removal efficiencies of toluene and COD, higher than 93% for all, and the advantage was greatest for the highest toluene loading, $0.12\;M/m^2-day$. The 1-mm carriers achieved superior performance by minimizing the negative effects of oxygen depletion, because they had 4.7 to 6.8 times thinner biofilm depths. The 1-mm carriers continued to provide protection from excess biomass detachment and inhibition from toluene. Finally, the 1-mm CBBR achieved volumetric removal capacities up to 300 times greater than demonstrated by other biofilters treating toluene and related volatile hydrocarbons.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.67-68
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• 2006

Organic light-emitting devices (OLEDs) with the high efficiency and long lifetime are of growing interest in next-generation displays. Among the factors influencing OLEDs properties, one of unstable factor is $Alq_3$ cationic species caused by the excess holes resided in $Alq_3$ layer. Therefore, we suppressed the accumulation of excess holes by using the mixed-hole transporting layer (MHTL) of NPB and CBP in multilayer green OLEDs. The devices with MHTL showed improved characteristics in the luminance efficiency and lifetime. More characteristics and the carrier transport mechanism will be discussed.

• 한국전기전자재료학회논문지
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• 제21권1호
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• pp.23-28
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• 2008

In this paper, transient characteristics of the Punch Through Insulated Gate Bipolar Transistor (PT-IGBT) have been studied. On the contrary to Non-Punch Through Insulated Gate Bipolar Transistor(NPT-IGBT), it has a buffer layer and reduces switching power loss. It has a simple drive circuit controlled by the gate voltage of the MOSFET and low on-state resistance of the bipolar junction transistor. The transient characteristics of the PT-IGBT have been analyzed analytically. Excess minority carrier and charge distribution in active base region, the rate of anode voltage with time are expressed analytically by adding the influence of buffer layer. The experimental data is obtained from manufacturer. The theoretical predictions of the analysis have been compared with the experimental data obtained from the measurement of a device(600 V, 15 A) and show good agreement.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.328.1-328.1
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• 2014

MOSFET degradation의 대부분은 hot-carrier injection에 의한 interface state (Dit)의 생성에서 비롯되며 따라서 본 연구에서는 신뢰성에 대한 한 가지 방법으로 Charge pumping method를 이용하여 MOSFET의 interface trap(Dit)의 변화를 측정하였다. 소스와 드레인을 ground로 묶고 게이트에 펄스를 인가한 후 Icp를 측정하여 Dit를 추출하였다. 온도를 293~343 K까지 5 K씩 가변했을 때 293K의 Icp(${\mu}A$)는 0.12 nA 313 K는 0.112 nA 343 K는 0.926 nA이며 Dit (cm-1/eV-1)는 $1.61{\times}10^{12}$ (Cm-2/eV-1) $1.49{\times}10^{12}$ (Cm-2/eV-1) $1.23{\times}10^{12}$ (Cm-2/eV-1)이다. 측정결과 Dit는 Icp가 높은 지점에서 추출되며 온도가 높아지게 되면 Icp전류가 낮아지고 Dit가 줄어드는 것을 볼 수 있다. 온도가 올라가게 되면 carrier들이 trap 준위에서 conduction band 위쪽에 이동하게 되어서 interface에 trap되는 양이 작아지게 된다. 그래서 이때 Icp를 이용해 추출한 Dit 는 실제로 trap의 양이 줄어든 것이 아니라 Thermal excess 현상으로 인해 측정되는 Icp의 양이 줄어든 것으로 분석할 수 있다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.524-526
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• 2009

The effects of In and Ga contents on characteristics of InGaZnO (IGZO) films grown by a sol-gel method and their thin film transistors (TFTs) have been investigated. Excess In incorporation into IGZO enhances the field effect mobilities of the TFTs due to the increase in conducting path ways, and decreases the grain size and the surface roughness of the films because more $InO_2^-$ ions induce cubic stacking faults with IGZO. Ga incorporation into results in decrease in carrier concentration of films and off-current of TFTs since Ga ion forms stronger chemical bonds with oxygen than Zn and In ions, acting as a carrier killer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.3-4
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• 2007

Orientational ordering of polar molecules and excess charges at the interface are main origins of surface polarization. For organic electronics, probing and control of these two surface polarization phenomena are key issues. In this presentation, I report a novel electrical measurement that can directly probe orientational dipolar motion in surface monolayers by Maxwell-displacement-current, and also report a novel optical technique that allows carrier motions in organic materials by measuring the optical second harmonic signals activated by the electric field. Then I discuss how the control of dipolar motions and carrier motions are linked to organic electronics applications such as organic field effect transistors.